Let me dispel the rumor, Carlos is not Irish / Mexican fusion food. That thought still makes me laugh after all these years. I originally thought it, too. Carlos is 1970's style Phoenix mexican food. What the heck is that, you ask? (I might ask what the heck Irish/Mexican fusion is too, but will drop it for now)
Carlos opened in the '70's with a few other local chains (Manuel's comes to mind) when Mexican food started gaining popularity in the suburbs here. They built on the existing sonoran style mex, toned down the spice and compensated with huge portions and about 3/4 pound of shredded cheese on everything. You get the obligatory free bottomless chips and salsa when you sit down. It's all very good. It's not gourmet by any means, and it won't remind anyone of their tia's cooking. But the food is still very good.
The Carlos on Bell is a nice place to visit. The manager gets to know all the regulars and the service is always good. It's a big place, so there's rarely a wait - a rarity in North Scottsdale most nights. Prices are cheap for what you get.
Carlos can make you very, very happy if you go in with the right expectations. If that expectation includes anything that even vaguely resembles Irish fare, go to the Tilted Kilt next door.